System for storing a radioactive salt solution

Abstract

An improved system for receiving and storing a radioactive salt solution, comprising a storage tank configured to receive the radioactive salt solution while preventing a criticality accident, a solution inlet for transporting the radioactive salt solution to the storage tank, an overflow bottle, and a lid that seals the top of the storage tank. The lid includes a side Y-shaped fitting having a side tube configured to direct the radioactive salt solution from the solution inlet into the storage tank, a vertical tube configured to direct gas from the storage tank to a ventilation system, and an overflow line configured to transport excess radioactive salt solution from the storage tank to an overflow storage tank. An air gap between the side tube and the solution inlet prevents the radioactive salt solution from flowing back into the solution inlet. The control system includes: a level switch configured to provide a signal that the storage tank contains the maximum volume of radioactive salt solution.

Description

Technical Field

[0001] The various exemplary embodiments disclosed herein generally relate to systems for storing toxic radioactive salt solutions. Background Art

[0002] Deficient acid uranyl nitrate solutions are used in the sol - gel process for fuel fabrication. However, such solutions are toxic, and thus a system is needed for safely storing unused or discarded uranyl nitrate solutions as well as other radioactive salt solutions. Additionally, the uranium concentration in deficient acid uranyl nitrate solutions is from 0.5 M to 3.5 M, and the pH value is from 0.5 to 2.8. Therefore, a system for storing uranyl nitrate solutions must be able to withstand exposure to highly acidic conditions.

[0003] Other radioactive salt solutions (including nitrates of various radioactive metals) can be used in the sol - gel process for fuel fabrication. Ceramic fuel elements based on uranium, thorium, and plutonium are made from acidic solutions of UO2(NO3)2 (uranyl nitrate), U(NO3)6 (uranium nitrate), K2UO2(SO4)2 (potassium uranyl sulfate), UO2(SO4) (uranyl sulfate), U(SO4)2 (uranium sulfate), uranium phosphate, Th(NO3)4, or Pu(NO3)4. Therefore, a system for safely storing unused or discarded radioactive salt solutions should be suitable for storing various radioactive metal salts.

[0004] In view of the above, there is a need to develop improved methods and systems for storing toxic radioactive salt solutions. Summary of the Invention

[0005] In view of the current need to store toxic, radioactive, or other hazardous liquid materials, a brief overview of the various embodiments is given. Some simplifications and omissions may be made in the following overview, which is intended to emphasize and introduce some aspects of the embodiments disclosed herein, rather than to limit the scope of the present invention. A detailed description of embodiments sufficient to allow a person of ordinary skill in the art to make and use the inventive concepts will be provided in the subsequent sections.

[0006] The various embodiments disclosed herein relate to a system for receiving and storing radioactive salt solutions, comprising:

[0007] A storage tank having a top and a bottom, the storage tank configured to receive radioactive salt solutions while preventing critical accidents, wherein the storage tank has a defined width;

[0008] A solution inlet for transporting radioactive salt solutions to the storage tank;

[0009] An overflow bottle;

[0010] A lid for sealing the top of the storage tank; and

[0011] An air gap between the side tube and the solution inlet is configured to prevent the radioactive salt solution from flowing back into the solution inlet.

[0012] In various embodiments, the lid includes a side Y-shaped fitting having:

[0013] A side tube configured to direct the radioactive salt solution from the solution inlet into the storage tank,

[0014] A vertical tube configured to direct gas from the storage tank to the ventilation system; and

[0015] An overflow line configured to transport excess radioactive salt solution from the storage tank to an overflow storage tank.

[0016] The system for receiving and storing the radioactive salt solution may further include a selector for the ventilation system, the selector being configured to receive gas from the storage tank, and a second air gap between the selector and the vertical tube, the second air gap being configured to prevent the radioactive salt solution from flowing into the selector.

[0017] In various embodiments, the system includes a control system having:

[0018] A level switch configured to provide a signal that the storage tank is full, i.e., the storage tank contains the maximum volume of radioactive salt solution;

[0019] A first valve configured to terminate the flow of the radioactive salt solution from the solution inlet to the side tube upon receiving a signal from the level switch; and

[0020] A second valve configured to:

[0021] Allow the radioactive salt solution to flow from the storage tank to the overflow line, and

[0022] Allow gas to flow from the storage tank to the selector.

[0023] The first valve is set to a normally closed state to prevent overfilling of the storage tank in case of a malfunction; and the second valve is set to a normally open state to prevent the radioactive salt solution from overflowing in case of a malfunction when filling the storage tank. The second valve is configured to close when the storage tank is not being filled or emptied, thereby preventing the escape of liquid or gas from the storage tank. In various embodiments, the first valve and the second valve are solenoid valves.

[0024] The system for receiving and storing the radioactive salt solution may further include a solution outlet located at the bottom of the storage tank, and a valve configured to allow the radioactive salt solution in the storage tank to flow through the solution outlet to empty the storage tank.

[0025] A system for receiving and storing a radioactive salt solution may include an input pump configured to pump the radioactive salt solution to a solution inlet, where the input pump stops pumping the radioactive salt solution upon receiving a signal from a level switch, thereby preventing overfilling of the storage tank.

[0026] In various embodiments, an overflow bottle in a system for receiving and storing a radioactive salt solution includes a container having a nozzle; and a lid that includes a vent configured to trap harmful vapors, an opening welded to an overflow line; and means for removably securing the lid to the nozzle of the container. The means for removably securing the lid to the nozzle of the container may include:

[0027] A three-clamp closure,

[0028] A clamp having C-shaped clamping portions connected by a hinge, the clamp configured to engage the outer perimeter of the lid and the outer perimeter of the nozzle; or

[0029] External threads on the nozzle of the container configured to mate with corresponding internal threads on the lid. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To better understand the various exemplary embodiments, reference is made to the accompanying drawings, in which:

[0031] Figure 1 A system for receiving and storing a radioactive salt solution is shown;

[0032] Figure 2 A control system for managing Figure 1 fluid flow in the system is shown;

[0033] Figures 3A to 3C A system for receiving and storing a radioactive salt solution is shown, including a storage tank configured to receive the radioactive salt solution; and a lid having a side Y-fitting;

[0034] Figure 4 A storage tank support plate is shown;

[0035] Figure 5 A storage tank mounted to a bracket using Figure 4 the storage tank support plate is shown; and

[0036] Figure 6 An overflow bottle in a system for Figure 1 is shown. DETAILED DESCRIPTION

[0037] Waste or unused acid deficient uranyl nitrate (ADUN) solution needs to be stored safely. Safe ADUN storage requires the storage tank to be geometrically safe to prevent the possibility of a criticality accident, i.e., the outer diameter of the storage tank is about 5 inches or less, 4.5 inches or less, or 4 inches or less. The storage tank must be resistant to chemical corrosion by concentrated nitric acid.

[0038] Although the storage of ADUN solution is of particular concern here, other radioactive salt solutions that can be used as precursors for forming radioactive ceramic nuclear fuel through the sol-gel process can also be stored using the system disclosed herein. Suitable radioactive salt solutions include acidic solutions of UO2(NO3)2 (uranyl nitrate), Th(NO3)4, Pu(NO3)4, and mixtures thereof. Radioactive salt solutions based on uranium, thorium, and plutonium can be acidic solutions of UO2(NO3)2 (uranyl nitrate), U(NO3)6 (uranium nitrate), K2UO2(SO4)2 (potassium uranyl sulfate), UO2(SO4) (uranyl sulfate), U(SO4)2 (uranium sulfate), uranium phosphate, Th(NO3)4, or Pu(NO3)4.

[0039] An acid deficient uranyl nitrate solution can be prepared by dissolving uranium oxide in an aqueous nitric acid solution to produce a uranium solution, placing the uranium solution in a sealed reaction chamber under a pressure of 5 to 40 atmospheres, and heating the uranium solution to a desired holding temperature between 150°C and 250°C. The uranium solution is held at the desired holding temperature for a desired holding time in a sealed container, and then the pressure and temperature of the uranium solution are reduced to obtain an acid deficient uranyl nitrate solution.

[0040] Once the acid deficient uranyl nitrate solution is prepared, it is converted into ceramic nuclear fuel particles by sol-gel methods known in the art. This conversion can be carried out immediately, or the acid deficient uranyl nitrate solution can be stored in an acid-resistant storage tank for later use.

[0041] Storing waste acid deficient uranyl nitrate (ADUN) requires a geometrically safe storage tank to prevent the possibility of a criticality accident. Generally, the storage tank can have any desired height, but must have a narrow width to avoid excessive accumulation of nuclear material at any point along the height of the storage tank. Since acid deficient uranyl nitrate is formed in a nitric acid solution, the storage tank must be resistant to chemical corrosion by concentrated nitric acid. The design of the storage tank must prevent the possibility of solution backflow to the solution inlet, which can be achieved by setting an air gap. The storage tank should be able to be sealed to simultaneously limit gas emissions and the spillage of ADUN solution from the storage tank.

[0042] The storage tank shall include a venting "pickup" to expel gas from the tank during filling and emptying operations, and the tank venting shall not be blocked unless all flows into or out of the tank are stopped. Other functions of the system include:

[0043] An overflow line capable of transporting excess fluid away from the tank;

[0044] A level switch for cutting off the inflow of ADUN solution into the tank before it is full; and

[0045] An optional demister inside the tank to limit the discharge of solution droplets into the venting pickup.

[0046] The system for receiving and storing radioactive salt solution disclosed herein incorporates the following improved design features:

[0047] A backflow-safe inlet flange (BSIF) that prevents solution backflow, provides an independent overflow path, interfaces with the facility ventilation, and allows the tank to be sealed to prevent steam release;

[0048] A criticality-safe tank support (CTS) that allows the tank to be mounted onto a process skid; and

[0049] A criticality-safe tank overflow bottle (CTOB) that provides a final sealing path for the solution in the event of an overflow.

[0050] Figure 1 A system for receiving and storing radioactive salt solution (such as ADUN) is shown. The system includes a storage tank 1 having an outer diameter y and a height x. In various embodiments, the storage tank 1 can be formed from a vertically oriented stainless steel tube with an outer diameter y of 5 cm to 12.5 cm (or 2 inches to 5 inches), or 10 cm to 11.5 cm (or 4 inches to 4.5 inches). Storage tanks of this diameter can be used in the nuclear fuel processing industry to prevent potential criticality accidents due to excessive accumulation of radioactive material at any given depth in the tank. In various embodiments, the tank can have a height x of 0.5 m to 5 m, 1 m to 4.5 m, 2 m to 4 m, or 3 m to 3.8 m. The tank can have an outer diameter y of 11 cm to 11.5 cm and a height x of 3.5 m to 3.6 m, and can be sealed at the top and bottom to produce a tank with a capacity of approximately 30 L. The storage tank 1 is geometrically safe to prevent the possibility of a criticality accident during radioactive salt storage, and the stainless steel material is chemically resistant to concentrated nitric acid.

[0051] The system disclosed herein is suitable for receiving and storing any solution containing fissile material within a fuel manufacturing facility. It can be used for any soluble salts of uranium, thorium, plutonium, or their oxidized forms. The only limitation is the material compatibility between the storage tank 1 and the solution. Solutions of salts of uranium, thorium, or plutonium in sulfuric acid, nitric acid, or phosphoric acid aqueous media are compatible with the stainless - steel storage tank 1. Since hydrochloric acid corrodes stainless steel, solutions of salts of uranium, thorium, or plutonium in hydrochloric acid aqueous media are incompatible with stainless steel. If it is necessary to store salts of uranium, thorium, or plutonium in hydrochloric acid aqueous media, the storage tank 1 can be constructed of glass tubing.

[0052] The upper end of the storage tank 1 is sealed with a reflux - preventing inlet flange, which includes a cover 2 having a flange. The cover 2 includes a side y - fitting 5 having a vertical tube and a side tube 4. The side tube 4 is configured to direct the radioactive salt solution from the solution inlet to the interior of the storage tank 1. The vertical tube in the side y - fitting 5 is configured to vent the gas in the storage tank 1 to a ventilation system. The storage tank 1 can include a demister 17 to enhance the removal of radioactive salt solution droplets from the gas discharged from the storage tank 1. The demister 17 can be a mesh coalescer to coalesce the droplets into larger droplets. The demister 17 can be a knitted wire mesh pad demister, a woven mesh demister, a non - woven mesh demister, or a demister formed by a plate or a series of plates with fine pores. The demister 17 is located in the storage tank 1, directly below the cover 2.

[0053] To prevent the radioactive salt solution from spilling in the case of an overflow of the storage tank 1 during filling, an overflow line 13 transports the excess radioactive salt solution from the side y - fitting 5 to a critical - safety storage tank overflow bottle 12 (shown in more detail in Figure 6 ). The tube in the side y - fitting 5 can have an outer diameter greater than the opening diameter in the overflow bottle 12. When the overflow line 13 leaves the fitting 5, its outer diameter can be the same as the inner diameter of the side y - fitting 5. To compensate for the difference between the initial outer diameter of the overflow line 13 and the opening diameter in the overflow bottle, one or more pipe reducers 8 and 9 can be used to reduce the diameter of the overflow line.

[0054] A valve 3 can be located between the cover 2 and the side y - fitting 5. When the valve 3 is open during filling the storage tank 1, the radioactive salt solution can enter the interior of the storage tank 1 from the side tube 4, and the gas in the storage tank 1 can be vented to the ventilation system through the vertical tube in the fitting 5. When the valve 3 is closed, the radioactive salt solution can be stored in the storage tank 1, preventing the solution from spilling or the gas from escaping. The valve 3 can be controlled by a controller 3a.

[0055] The storage tank 1 can include a solution outlet 14 at the bottom of the tank, allowing the contents of the storage tank 1 to be emptied and recovered. A valve 7 can be used to open or close the solution outlet 14. A side stream 15 opened or closed by a valve 6 can be used to sample the radioactive salt solution in the storage tank 1.

[0056] The overflow line 13 may be installed with an observation glass 16. The interior of the overflow line 13 can be monitored by a camera or an optical sensor 10 to detect the radioactive salt solution in the overflow line. If a radioactive salt solution is detected in the overflow line 13, the sensor 10 can send a signal to the CPU 11.

[0057] In various embodiments, the storage tank 1 is made of a stainless steel pipe with a nominal pipe size (NPS) of 4 to 5, and as required, the cover 2 at the top of the storage tank 1 is a flange cover for a NPS 4 pipe or a NPS 5 pipe. Two ports are machined on the flange cover: a 3 / 4” port for a level switch and a 2” port for connecting to a side Y fitting through a valve 3. In various embodiments, the inlet assembly includes the following components:

[0058] The valve 3, which can be a 2” solenoid valve; and

[0059] The side Y fitting 5, which can be a 2” side Y, improved with a 2” overflow pipe and a side pipe 4 with a funnel-shaped opening.

[0060] Figure 2 A control system for managing Figure 1 the input solution and the exhaust gas flow rate in the system is shown. The cover 2 on the storage tank 1 includes a level switch 31 configured to provide a signal indicating that the storage tank 1 contains the maximum volume of radioactive salt solution (i.e., the storage tank 1 is full). The first valve 21 is configured to terminate the flow of the radioactive salt solution from the solution input 20 to the side pipe 4 upon receiving a signal from the level switch. The second valve 3, also shown in Figure 1 is configured to:

[0061] allow the radioactive salt solution to flow from the storage tank 1 to the overflow line 13 ( Figure 2 not shown in

[0062] ), and

[0063] allow gas to flow from the storage tank 1 to the ventilation system through the ventilation selector 23. Figure 1is the same as or different from the CPU 11 in. When receiving a signal from the level switch 31, the CPU 22 sends a first signal to the input pump, which pumps the radioactive salt solution to the solution input 20, where the first signal closes the input pump to prevent the storage tank 1 from being overfilled. The CPU 22 also sends a second signal to the valve 21 to close the valve 21 to terminate the flow of the radioactive salt solution from the solution input 20 to the side tube 4, also to prevent the storage tank 1 from being overfilled. The CPU 22 sends a third signal to the valve 3 to open the valve 3 to allow the radioactive salt solution to flow from the storage tank 1 to the overflow line 13 and allow gas to flow from the storage tank 1 to the ventilation selector 23.

[0064] The valve 21 is set to a normally closed state, so that if the valve 21 fails, it will fail in the closed position to prevent the storage tank from being overfilled. The valve 21 is designed to cut off the flow of the solution input. When filling the storage tank, the CPU 22 sends a signal to the valve 21 to open, thereby allowing the radioactive salt solution to flow into the storage tank 1.

[0065] The valve 3 is set to a normally open state, so that if the valve 3 fails, it will fail in the open position to prevent the radioactive salt solution from overflowing when filling the storage tank. When the storage tank is not filled or emptied, the valve 3 closes to seal the radioactive salt solution and steam in the storage tank 1, thereby limiting emissions that may be radioactive or hazardous. During normal operation, the valve 3 and the valve 21 work together to allow flow only under conditions that prevent backflow.

[0066] In various embodiments, the valve 3 and the valve 21 are remotely actuated valves. Suitable remotely actuated valves include air-actuated pneumatic valves, motor-driven valves, and solenoid valves.

[0067] Figures 3A to 3C An embodiment of the disclosed system for receiving and storing radioactive salt solution is shown. The system includes a storage tank 1, the outer diameter y of which is, for example, 4.5 inches and the height x of which is, for example, 141 inches. Figure 3A and 3B The bottom of the storage tank 1 is shown, which includes a flange 37 and a radioactive salt solution outlet having a valve 38.

[0068] Figure 3A and Figure 3C The top of the storage tank 1 is shown, including a cover 2. The cover 2 includes a level switch 31, and the level switch 31 is installed in the first opening of the cover 2 for Figure 2Control system. The side Y-shaped fitting 5 is connected to the second opening in the lid 2, and the valve 36 is located therebetween. When the storage tank is being filled, the radioactive salt solution flows from the solution inlet 34 through the valve 35 to the side tube 4 of the side Y-shaped fitting 5. During the filling operation, both the valve 35 and the valve 36 are open, allowing the radioactive salt solution to flow from the inlet 34 through the side Y-shaped fitting and enter the storage tank 1 through the valve 36. After filling the storage tank, both the valve 35 and the valve 36 are closed to prevent the radioactive salt solution from overflowing.

[0069] The overflow pipe 32 extends from the vertical tube of the side Y-shaped fitting 5. If the storage tank 1 is overfilled during the filling operation, the excess solution may flow back into the side Y-shaped fitting. This solution is discharged into an overflow bottle through the overflow pipe 32 (as Figure 1 shown). This prevents the excess solution from overflowing from the opening of the side tube 4, where the solution is received from the inlet 34 or from the ventilation opening in the vertical tube of the side Y-shaped fitting 5.

[0070] As Figure 3C shown, the ventilation selector 33 is shaped like an inverted funnel. The gas inside the storage tank 1 may be radioactive or contain nitric acid vapor, and during the filling operation, these gases can escape from the storage tank 1 through the valve 36 and pass through the vertical tube of the side Y-shaped fitting 5. Suction can be applied to the ventilation selector 33 so that the gas escaping from the storage tank 1 is sucked into the ventilation selector 33.

[0071] The side Y-shaped fitting 5 provides an independent ventilation path through the vertical tube, an independent overflow path through the overflow pipe 32, and a solution input through the side tube 4. Positioning the Y-shaped fitting 5 above the valve 36 allows the storage tank 1 to be sealed without providing a means to block the ventilation path. During operation, the ventilation path through the vertical tube of the fitting 5 must be opened passively. If the ventilation path and the solution input were separate ports in the lid 2, the valve on the ventilation path would allow the valve to fail in the open position, so the valve on the ventilation path would not be fail-safe. Since both the ventilation selector 33 and the solution inlet 34 are located above the valve 36, if the valve 36 is closed, the storage tank does not operate and the gas cannot escape from the storage tank. Therefore, the ventilation selector and the inlet filling are connected by this assembly.

[0072] Figures 3A to 3C The system includes means to prevent backpressure from flowing back to the solution inlet 34. This backflow is caused by a downstream pressure greater than the inlet pressure. As Figure 3C shown, backflow can be prevented by an air gap between the inlet 34 and the side tube 4. If desired, the air gap can be replaced by a mechanical backflow prevention device to form a physical barrier against backflow. The mechanical backflow prevention device can be a pressure relief principle assembly, a double check valve assembly, or a pressure vacuum breaker assembly.

[0073] A second air gap can be introduced between the ventilation selector 33 and the opening in the vertical pipe of the side Y-shaped fitting 5. This air gap prevents the radioactive salt solution in the side Y-shaped fitting 5 from being sucked into the ventilation selector 33.

[0074] Reference Figure 3B and Figure 3C , during the filling operation, both valve 35 and valve 36 are opened to allow the incoming solution to enter the storage tank 1 through valve 35 and valve 36, while allowing gas to flow through valve 36. During the filling operation, valve 38 is closed to hold the solution in the storage tank 1. After filling is completed, both valve 35 and valve 36 are closed to prevent overfilling of the storage tank or to prevent gas or radioactive salt solution from spilling out of the storage tank 1; and valve 38 is closed. When emptying the storage tank 1, valve 38 is opened to allow the radioactive salt solution to flow out of the storage tank 1, and valve 36 is opened to allow the atmosphere to enter the storage tank 1 and prevent the formation of a vacuum inside the storage tank.

[0075] Figure 4 Shows a critical safety storage tank support for a system for Figure 3A , which includes a storage tank support plate 44 with a length and width of m. The storage tank support plate includes a central hole 41 with a diameter of y', where y' = y + Δ. The diameter y' is slightly larger than the outer diameter of the storage tank 1 by a distance Δ to allow the lower end of the storage tank 1 to slide through the opening of the central hole 41 without interference. The hole 42 is configured to receive bolts passing through the Figure 3B flange 37, where the holes 42 are arranged on a circle concentric with the central hole 41. In various embodiments, each hole 42 has a corresponding hole 42 on the opposite side of the central hole 41, where each pair of opposite holes 42 are separated by a distance p. The storage tank support plate 44 also includes holes 43 along the edge of the plate 44. The holes 43 are configured to receive bolts passing through the support slide (as Figure 5 shown). Each pair of adjacent holes 43 are separated by a distance n. Each hole 43 is separated from the edge of the plate 44 by a distance q.

[0076] Figure 5 Shows a storage tank installed on the Figure 4 storage tank support plate 44 of Figure 3B , where the plate 44 is shown in cross-section. The storage tank 1 has an outer diameter of y' and an inner diameter of y. The storage tank 1 passes through the central hole 41 of the plate 44. The flange 37 on the storage tank 1 is connected to the plate 44 with bolts 52 having heads 51. The bolts 52 pass through the holes 42 in the plate 44 and are fixed in place with nuts 53. The storage tank support plate 44 is in turn connected to the support slide 56 with bolts 54. The bolts 54 pass through the holes 43 in the plate 44 (as Figure 4 shown) and are fixed in place with nuts 53. The system includes a storage tank support plate 44 bolted to the flange 37, providing a firm support for the storage tank. As Figure 5 shown, the storage tank 1 includes an outlet 57 leading to valve 38.

[0077] In various embodiments, an NPS 4 pipe flange or an NPS 5 pipe flange is used as flange 37 and is bolted to plate 44. Flange 37 is also fixed to the outer surface of storage tank 1 in a manner very similar to how lid 2 is fixed to the upper end of storage tank 1. Plate 44 is fixed to support slide 56. This provides a strong support for storage tank 1.

[0078] Figure 6 An overflow bottle 12 for connection to Figure 1 is shown. The bottle 12 has a volume of 0.5 liters to 5 liters, 0.7 liters to 4 liters, 0.75 liters to 2.25 liters, or 0.8 liters to 1.2 liters. The bottle 12 has a closure 64 having a first opening configured to receive vent 61, where vent 61 vents gas from inside the bottle 12. The closure 64 has a second opening 62 adapted to connect to overflow line 13. In various embodiments, the bottle 12 and the closure 64 are made of acid-resistant material, such as stainless steel. The opening 62 can be butt-welded to the overflow line 13. A device 63 is provided for fixing the bottle 12 to the closure 64. In various embodiments, the closure 64 can have a skirt with internal threads, and the bottle 12 can have an opening with external threads corresponding to the internal threads such that the bottle 12 can be screwed off the closure 64. In various embodiments, the closure 64 and the bottle 12 can be fixed together with a three-clamp closure or a clamp having C-shaped clamping portions connected by a hinge, the clamp being configured to engage the outer periphery of the lid and the outer periphery of the mouth.

[0079] Although the various exemplary embodiments have been described in detail with particular reference to certain of their exemplary aspects, it should be understood that the present invention is capable of other embodiments and that its details can be modified in various obvious aspects. It will be apparent to those skilled in the art that changes and modifications can be made within the spirit and scope of the present invention. Accordingly, the foregoing disclosure, description, and drawings are for illustrative purposes only and do not in any way limit the present invention, which is defined only by the claims.

Claims

1. A system for receiving and storing radioactive salt solution, comprising: A storage tank having a top and a bottom, the storage tank configured to receive a radioactive salt solution while preventing a criticality accident, wherein the storage tank has a defined width; A solution inlet for transporting the radioactive salt solution to the storage tank; An overflow bottle; A lid sealing the top end of the storage tank, the lid including a side Y-shaped fitting having: A side tube configured to direct the radioactive salt solution from the solution inlet into the storage tank, A vertical tube configured to direct gas from the storage tank to a ventilation system; And An overflow line configured to transport excess radioactive salt solution from the storage tank to the overflow bottle; and a first air gap between the side tube and the solution inlet configured to prevent the radioactive salt solution from flowing back into the solution inlet.

2. The system according to claim 1, further comprising a selector for the ventilation system and a second air gap between the selector and the vertical pipe, the selector being configured to receive gas from the storage tank, and the second air gap being configured to prevent the radioactive salt solution from flowing into the selector.

3. The system according to claim 2, further comprising a control system, the control system comprising: A level switch configured to provide a signal that the storage tank contains a maximum volume of radioactive salt solution; A first valve configured to terminate the flow of the radioactive salt solution from the solution inlet to the side tube upon receipt of a signal from the level switch; And A second valve configured to: Allow the radioactive salt solution to flow from the storage tank to the overflow line, and Allow gas to flow from the storage tank to the selector.

4. The system according to claim 3, wherein: The first valve is set to a normally closed state to prevent overfilling of the storage tank in case of a malfunction; The second valve is set to a normally open state to prevent spillage of the radioactive salt solution in case of a malfunction when filling the storage tank; and The second valve is configured to close when the storage tank is not filled or emptied.

5. The system according to claim 3, wherein, The first valve and the second valve are solenoid valves.

6. The system according to claim 3, further comprising: An input pump configured to pump the radioactive salt solution to the solution inlet, wherein the input pump stops pumping the radioactive salt solution upon receipt of a signal from the level switch.

7. The system according to claim 1, further comprising: A solution outlet located at the bottom of the storage tank; And A valve configured to allow the radioactive salt solution in the storage tank to flow through the solution outlet when the valve is in an open state.

8. The system according to claim 1, wherein the overflow bottle comprises: A container having a nozzle; A lid including: A vent configured to trap harmful vapors, An opening welded to the overflow line;And Means for removably securing the lid to the nozzle of the container.

9. The system according to claim 8, wherein, The means for removably securing the lid to the nozzle of the container includes: A clamp having C-shaped clamping portions connected by a hinge, the clamp configured to engage the outer periphery of the lid and the outer periphery of the nozzle.

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